diff --git a/source/isaaclab/changelog.d/locomotion-newton-tuning.minor.rst b/source/isaaclab/changelog.d/locomotion-newton-tuning.minor.rst
new file mode 100644
index 000000000000..dd8f9fe06402
--- /dev/null
+++ b/source/isaaclab/changelog.d/locomotion-newton-tuning.minor.rst
@@ -0,0 +1,5 @@
+Added
+^^^^^
+
+* Added :func:`~isaaclab.envs.mdp.body_lin_vel_out_of_manual_limit` to terminate environments when an
+  articulation body exceeds a configured linear speed.
diff --git a/source/isaaclab_tasks/changelog.d/locomotion-newton-tuning.rst b/source/isaaclab_tasks/changelog.d/locomotion-newton-tuning.rst
new file mode 100644
index 000000000000..a0f0b89779d1
--- /dev/null
+++ b/source/isaaclab_tasks/changelog.d/locomotion-newton-tuning.rst
@@ -0,0 +1,5 @@
+Fixed
+^^^^^
+
+* Fixed Newton MJWarp locomotion training instability by tuning contact capacity and parameters, adjusting the
+  ANYmal-D initial height, and terminating excessively fast bodies.
diff --git a/source/isaaclab_tasks/isaaclab_tasks/core/velocity/config/anymal_d/rough_env_cfg.py b/source/isaaclab_tasks/isaaclab_tasks/core/velocity/config/anymal_d/rough_env_cfg.py
index f79379bbc06e..5a8421445975 100644
--- a/source/isaaclab_tasks/isaaclab_tasks/core/velocity/config/anymal_d/rough_env_cfg.py
+++ b/source/isaaclab_tasks/isaaclab_tasks/core/velocity/config/anymal_d/rough_env_cfg.py
@@ -19,8 +19,7 @@ class AnymalDRoughEnvCfg(LocomotionVelocityRoughEnvCfg):
     def __post_init__(self):
         super().__post_init__()
 
-        # sim
-        # lower margin to avoid self-collision
-        self.sim.physics.newton_mjwarp.default_shape_cfg.margin = 0.001
         # scene
-        self.scene.robot = ANYMAL_D_CFG.replace(prim_path="{ENV_REGEX_NS}/Robot")
+        self.scene.robot = ANYMAL_D_CFG.replace(
+            prim_path="{ENV_REGEX_NS}/Robot", init_state=ANYMAL_D_CFG.init_state.replace(pos=(0.0, 0.0, 0.65))
+        )
diff --git a/source/isaaclab_tasks/isaaclab_tasks/core/velocity/config/cassie/rough_env_cfg.py b/source/isaaclab_tasks/isaaclab_tasks/core/velocity/config/cassie/rough_env_cfg.py
index 957cb8d0f614..54832022cca8 100644
--- a/source/isaaclab_tasks/isaaclab_tasks/core/velocity/config/cassie/rough_env_cfg.py
+++ b/source/isaaclab_tasks/isaaclab_tasks/core/velocity/config/cassie/rough_env_cfg.py
@@ -57,7 +57,7 @@ class CassieRoughEnvCfg(LocomotionVelocityRoughEnvCfg):
 
     def __post_init__(self):
         super().__post_init__()
-
+        self.sim.physics.newton_mjwarp.num_substeps = 2
         # scene
         self.scene.robot = CASSIE_CFG.replace(prim_path="{ENV_REGEX_NS}/Robot")
         self.scene.robot.actuators["legs"].armature = preset(default=0.0, newton_mjwarp=0.02)
diff --git a/source/isaaclab_tasks/isaaclab_tasks/core/velocity/config/g1/rough_env_cfg.py b/source/isaaclab_tasks/isaaclab_tasks/core/velocity/config/g1/rough_env_cfg.py
index 415b816c323a..b36da32002ad 100644
--- a/source/isaaclab_tasks/isaaclab_tasks/core/velocity/config/g1/rough_env_cfg.py
+++ b/source/isaaclab_tasks/isaaclab_tasks/core/velocity/config/g1/rough_env_cfg.py
@@ -110,7 +110,7 @@ class G1RoughEnvCfg(LocomotionVelocityRoughEnvCfg):
 
     def __post_init__(self):
         super().__post_init__()
-
+        self.sim.physics.newton_mjwarp.num_substeps = 2
         # scene
         self.scene.robot = G1_MINIMAL_CFG.replace(prim_path="{ENV_REGEX_NS}/Robot")
         self.scene.height_scanner.prim_path = "{ENV_REGEX_NS}/Robot/torso_link"
diff --git a/source/isaaclab_tasks/isaaclab_tasks/core/velocity/velocity_env_cfg.py b/source/isaaclab_tasks/isaaclab_tasks/core/velocity/velocity_env_cfg.py
index 6e9dd535159c..796cf9591a6a 100644
--- a/source/isaaclab_tasks/isaaclab_tasks/core/velocity/velocity_env_cfg.py
+++ b/source/isaaclab_tasks/isaaclab_tasks/core/velocity/velocity_env_cfg.py
@@ -52,8 +52,8 @@ class RoughPhysicsCfg(PresetCfg):
     physx = PhysxAutoCfg(isaacsim_physx=isaacsim_physx, ovphysx=ovphysx)
     newton_mjwarp = NewtonCfg(
         solver_cfg=MJWarpSolverCfg(
-            njmax=200,
-            nconmax=100,
+            njmax=1000,
+            nconmax=300,
             cone="pyramidal",
             impratio=1.0,
             integrator="implicitfast",
@@ -62,10 +62,7 @@ class RoughPhysicsCfg(PresetCfg):
         collision_cfg=NewtonCollisionPipelineCfg(max_triangle_pairs=2_500_000),
         num_substeps=1,
         debug_mode=False,
-        # 1 cm shape margin is the single most important Newton setting for rough
-        # terrain — without it, non-AnymalD robots fail to learn stable contact
-        # on triangle-mesh terrain. See isaaclab_newton 0.5.22 changelog.
-        default_shape_cfg=NewtonShapeCfg(margin=0.01),
+        default_shape_cfg=NewtonShapeCfg(margin=0.0, ke=160000.0, kd=1100.0),
     )
     default = isaacsim_physx